Advantages of a NAS at home

My configuration at home features a simple portable HDD that is attached to the router via USB (2.0). This solution has some advantages:

Very portable

Extensible

Low power consumption

Easy to configure

Low maintenance

There are, however, some severe problems. One the one hand I get very low access times from any computer. The computers access the drive via Wifi, so the bandwidth and latency is not high by definition. However, accessing a directory structure or reading out file attributes takes far too long. Also there is no backup of the given data. Therefore such a solution can only be used for backups.

Lately I am interested in replacing this solution (the USB connected portable Seagate HDD) with a NAS. Of course some 1-HDD solution could be an appropriate replacement, but why shouldn't I use this chance for a more secure and robust solution?

I made a really small benchmark, testing read and write performance of the current solution vs. a possible solution in form of a WD Book Live Duo device. This NAS features 2 HDD that can be configured as RAID 0/1 (in my case RAID 1). There are several possible models, but the 8 TB (2x 4 TB) seems to be adequate.

Reading data resulted in an interesting plot:

We can see that the performance is literally off-the-roof for the NAS system. It is even beyond the bandwidth of my local Wifi, which makes me wonder if there is some kind of caching going on. Either way, the read time for small files is much higher for the NAS.

Writing looks interesting as well. Here we do not see such a small latency and high performance for small files. Still the NAS is around 30% faster than my previous USB attached storage solution.

Now the only remaining question is: What kind of NAS? Obviously the WD Book Live Duo seems like a great product, especially if one considers to get 8 TB for less than 500 € in a fully-configurable NAS device. But there are also other really interesting options. The probably most interesting solution without any pre-installed hard disks is the Synology DiskStation DS213J NAS-Server. Here one gets a fully configurable NAS server with low power consumption and neat features, such as the private cloud solution.